FAST 102mm intake too big for a 390ci......
12-06-2014, 09:08 AM
#2
There is no such thing as too big on a modern fuel injected engine. This isn't a carbed motor where you can run it rich by mixing too much fuel and air. The pcm tells motor to only mix as much fuel as is needed for its cycle, something carbs could never do.
Think of an intake as a large air tank and the motor being a ball valve at the bottom. A stock intake on a big motor (Big ball valve) will empty the tank faster than it can refill itself (plenum volume and tb size) causing vacuum aka restriction. A fast 102 is like doubling the tank size and tank inlet (tb size) but keeping the same ball valve so now that same motor will not empty the tank and the intake will keep a surplus of air not choking the engine.
Now there are a lot more things that go into intake sdesign like runner length, flow etc but thats a good metaphor for the size. In short no its not too big get it, I run that same setup on my car in sig and it picked up huge over the ls6 setup. I'm also right there in pompano so if you need a hand let me know!
Think of an intake as a large air tank and the motor being a ball valve at the bottom. A stock intake on a big motor (Big ball valve) will empty the tank faster than it can refill itself (plenum volume and tb size) causing vacuum aka restriction. A fast 102 is like doubling the tank size and tank inlet (tb size) but keeping the same ball valve so now that same motor will not empty the tank and the intake will keep a surplus of air not choking the engine.
Now there are a lot more things that go into intake sdesign like runner length, flow etc but thats a good metaphor for the size. In short no its not too big get it, I run that same setup on my car in sig and it picked up huge over the ls6 setup. I'm also right there in pompano so if you need a hand let me know!
12-06-2014, 05:44 PM
#3
There is no such thing as too big on a modern fuel injected engine. This isn't a carbed motor where you can run it rich by mixing too much fuel and air. The pcm tells motor to only mix as much fuel as is needed for its cycle, something carbs could never do.
Think of an intake as a large air tank and the motor being a ball valve at the bottom. A stock intake on a big motor (Big ball valve) will empty the tank faster than it can refill itself (plenum volume and tb size) causing vacuum aka restriction. A fast 102 is like doubling the tank size and tank inlet (tb size) but keeping the same ball valve so now that same motor will not empty the tank and the intake will keep a surplus of air not choking the engine.
Now there are a lot more things that go into intake sdesign like runner length, flow etc but thats a good metaphor for the size. In short no its not too big get it, I run that same setup on my car in sig and it picked up huge over the ls6 setup. I'm also right there in pompano so if you need a hand let me know!
Think of an intake as a large air tank and the motor being a ball valve at the bottom. A stock intake on a big motor (Big ball valve) will empty the tank faster than it can refill itself (plenum volume and tb size) causing vacuum aka restriction. A fast 102 is like doubling the tank size and tank inlet (tb size) but keeping the same ball valve so now that same motor will not empty the tank and the intake will keep a surplus of air not choking the engine.
Now there are a lot more things that go into intake sdesign like runner length, flow etc but thats a good metaphor for the size. In short no its not too big get it, I run that same setup on my car in sig and it picked up huge over the ls6 setup. I'm also right there in pompano so if you need a hand let me know!
I just remember reading someone on here....((can't find the thread))....a guy that built I think a 427ci and he gained power and torque going from a FAST 102mm to a FAST 92mm......
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12-08-2014, 05:05 AM
#5
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Pompano, thats right.....I'll be having Lashway do the intake/TB/head swap, cam and re-tune.
I just remember reading someone on here....((can't find the thread))....a guy that built I think a 427ci and he gained power and torque going from a FAST 102mm to a FAST 92mm......
.
I just remember reading someone on here....((can't find the thread))....a guy that built I think a 427ci and he gained power and torque going from a FAST 102mm to a FAST 92mm......
.
12-08-2014, 02:09 PM
#6
If you have high flowing heads and matching cam, then you want as much air as possible coming in. No way the FAST is too big.
Maybe if that engine had stock heads, cam and iron manifolds a big FAST might not do too much, but you are not in that position.
Maybe if that engine had stock heads, cam and iron manifolds a big FAST might not do too much, but you are not in that position.
